Semiconductor fabrication processes frequently involve patterning of electrical devices and interconnections from semiconductive materials. A method of accomplishing such patterning is to treat a semiconductive material such that one portion is selectively etchable relative to another portion. For instance, silicon-comprising semiconductive materials can be treated with a dopant to render certain portions selectively etchable relative to other portions. Specifically, if portions of a silicon-comprising material are doped with phosphorus, such portions will be selectively etchable relative to other portions that are not doped with phosphorus under etching conditions utilizing a base, such as, for example, KOH, NaOH, NH.sub.4 OH, and tetramethyl ammonium hydroxide (TMAH).
Although the above-discussed methodology enables patterning of a silicon-comprising material, the processing can be difficult to incorporate into applications in which it is a doped silicon-comprising material that is ultimately desired. Specifically, since the above-discussed methodology selectively removes doped silicon relative to undoped silicon, patterning incorporating such methodology ultimately forms an undoped silicon-comprising material. In many semiconductor processing applications, it is ultimately desired to form a doped silicon-comprising material. For instance, in applications in which it is desired to have the silicon-comprising material be conductive, it is ultimately desired that the silicon-comprising material be doped. In such applications, the above-discussed methodology for selectively removing a doped silicon-comprising material relative to an undoped silicon-comprising material is exactly backwards of what would be desired.